@article{CM_1965-1966__17__156_0,
     author = {Hsiang, Fu Cheng},
     title = {On the absolute summability factors of {Fourier} series at a given point},
     journal = {Compositio Mathematica},
     pages = {156--160},
     publisher = {Kraus Reprint},
     volume = {17},
     year = {1965-1966},
     mrnumber = {208268},
     zbl = {0178.06501},
     language = {en},
     url = {http://archive.numdam.org/item/CM_1965-1966__17__156_0/}
}